Resurgence of vitamin D deficiency rickets in the UK

Zulf Mughal

Rickets is a disease in which there is failure of mineralisation the growth plate and osteoid matrix. It is a disorder of the growing child which manifests during infancy (<18 months of age) and during the adolescent growth spurt. In the UK nutritional rickets is caused by vitamin D deficiency, although dietary calcium deficiency might exacerbate the disease. In humans the main source of vitamin D is by the conversion of 7-dehydrocholesterol in the skin to cholecalceferol upon exposure to suns ultraviolet B (UVB) radiation. 1,25-dihydroxyvitamin D, the active metabolite of vitamin D is crucially important for calcium & phosphorous homeostasis and skeletal mineralisation. In 19th and early 20th centuries, vitamin D deficiency rickets was rampant among the underprivileged children living in polluted industrialised cities in the UK. Implementation of measures to control atmospheric pollution, better housing conditions and availability of subsidised vitamin D-fortified welfare foods & supplements lead to disappearance of rickets among white-Caucasian children, by mid 1950s. From 1960s onwards rickets re-emerged as an important health problem among toddlers and adolescents of immigrants from South Asian Countries (India, Pakistan & Bangladesh) and West Indies. Residence in northern latitudes, skin pigmentation and sunshine avoidance for religious & cultural reasons lead to reduced cutaneous vitamin D synthesis in these children. Rachitogenic diet also contributed to vitamin D deficiency. Vitamin D supplementation was shown to be an effective way of reducing rickets in these at risk infants, and this was an important pillar of the Stop Rickets Campaign, which was launched in 1981. Over the last 15 years there have been several reports of re-emergence of florid rickets among ethnic minority children in the UK. Infants most at risk are those born to vitamin D deficient mothers and who are fed on breast milk (contains ~ 40 IU vitamin D per litre), and not provided vitamin D supplements after birth. Some such infants have also developed potentially fatal heart failure secondary to dilated cardiomyopathy. Thus, it is crucially important to provide vitamin D supplements to mothers during pregnancy and lactation. It is equally important to provide vitamin D supplements to vulnerable infants after birth.

Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.